Malaysian Jet

Quote: rxwine

First plane taken over by a sophisticated computer virus, similar to Stuxnet.

Boeing is not Fly by wire... physical movement of the control yoke over rides the computer input and there are circuit breakers galore to take anything electronic offline.

There are some misstatements above about radar and tracking I'd like to correct.

Radar products are generally layered. The very bottom layer is called primary radar and works by echo-location. That is, the antenna sends out a radio wave in all directions, thrown from a rotating antenna, with a receiver mounted on the same antenna, turning at a very specific speed (usually between 4 and 8 seconds per rotation). Anything of its own signal heard back, it notes the direction of the return and the length of time the echo took to return. The direction corresponds to which radius, from the center of the radar's position on the screen (the sweep) the target will paint, and how long the signal takes to return corresponds to what point on that radius the target will be painted. So you have distance and direction relative to one point, but no altitude. You also paint flocks of birds, trucks moving over bridges, precipitation, high buildings, anything that's moving above the radar horizon (called azimuth). The range of those used by approach controls is reliable to 60-70 NM from the antenna; the range of en route systems is 250-400 NM. (NM is nautical miles, which are slightly longer than statute miles, and an increment of a degree of longitude).

There are various filters that help with some of the extraneous targets, but you pay a price in reducing target signals. There is also a lot of skill in reading these returns and learning what to ignore and what is significant. The most important factor for governments is usually the cost of maintaining this system; it's very expensive to install and maintain. For that reason, many governments around the world, and in the US to some extent, these systems have been decommissioned for many civilian operations. There is a safety cost associated with the loss of this information, both in aviation and in the national defense of a country, so some militaries have a partial to complete deployment of them, especially on their coastlines. So the military in Malaysia having a return that they acquired about 200 miles to the east, kept over the mainland, and lost 240 miles west over water, is very consistent with the range of their equipment. It's ground-based and requires a heavy, stable platform, so they can't place stations on water for detection beyond that range.

Many of these primary systems have been hybridized in the display to a digital signal of the primary, not the raw return. The digital signal will have been filtered to disallow most precipitation return, bird flocks, stationary targets, and other clutter. The digitizer will also filter out returns that are not consistent along a track and speed of 3 consistent hits at a minimum to be an airplane. Again, information is lost and certain targets are not detected. This is a possibility here, and was also a factor in 9-11, when our goverment was in the process of "saving" money by turning them off. (They have turned many of them back on as a result.)

The 2nd layer of radar is called a secondary return, and requires a transponder on the aircraft. The main bang (center of the radar) turns at the same rates and ranges as primary if they're co-located, but has an interrogator in the middle "saying 'Who's out there'" constantly. Each aircraft dials in their assigned code and their transponder answers back "It's me", verifying they're an airplane (not a bird or whatever), strengthening the target, and displaying that beacon code on the scope. The airplane transponder (these days) almost always broadcasts their altitude as well, as ATC radar asks at all azimuths simultaneously and doesn't differentiate for altitude.

The 3rd layer, what you actually see if you look at a picture of a radar scope, is the computer overlay of information, called a data tag, associated with each beacon code. This can be misleading, because these data tags are showing both information that's slightly stale, and the tags are programmed to "coast" along a route and speed consistent with the last confirmed position, awaiting updates from the beacon. This can lead to tags jumping or misleading the operator into thinking an aircraft is somewhere else (or even still airborne) when it's not.

I've skipped a lot, trying to pick out what's pertinent to this mystery, but this is how what everyone's saying over there can be correct at the same time, even though it seems contradictory. The tag could have continued on the projected track, without a real target after transponder signal loss, which would not be unusual at the range from the shore, towards Vietnam for an hour, easily. The transponders could have been turned off deliberately, making it difficult to track, and then an untracked turn could be made if the aircraft went deliberately silent. The military over there may be the only agency with a primary system, but they don't routinely track civilian targets, and if they're looking at the raw return, would have no information about what the target was that crossed from east to west at about the right time; chances are very high that they only found that track after going back and replaying their radar tapes, not that they knew what they were looking at. They have no way of directly verifying that track was the missing airplane; they're just correlating what they do know of its last verified position to an unexplained target going the "wrong" way. Or the whole thing could be in the water anywhere from where they started looking to well beyond where the military lost the signal towards the Indian Ocean. Or the whole aircraft could have been hijacked and landed secretly; they had about 6 more hours flying time in fuel when they were last in a confirmed position.

Chinese satellite may have spotted debris near the original location when transponder went down.


Image is dated March 9, but the Chinese may have not found it until today.

Quote: rxwine

I could of sworn I once saw a video where all these plane crash cockpit recordings were reenacted by actors as if a camera was there capturing it, but I can't find a video of it, so maybe not. I remember it being really creepy.

This is likely what you're thinking of, from the Discovery Channel. It was also on the Wings channel (an offshoot of History) before it became the Military channel. Very good program, it's had 13 seasons now.

Quote: Fleastiff

Boeing is not Fly by wire... physical movement of the control yoke over rides the computer input and there are circuit breakers galore to take anything electronic offline.

Ah,

Okay, plane collided with Chinese (or other maybe) military black project plane. Could explain slow response, but not some other things. A black project plane might have the capability to knock out transmissions of other planes which would explain going silent. Knocking out communications is a handy exploit for military, if they could do it. But may have collided by accident. The crippled civilian airliner was able to fly several hundred miles without communication, but eventually ditched in the sea.

I could see the Chinese being hesitant to make full disclosure and making things confusing. I don't think this is a very good possibility though.

Got a feeling this is all going to be more Occam's razor than complicated.

Quote: rxwine

Got a feeling this is all going to be more Occam's razor than complicated.

Occam will hopefully be involved in the fault analysis.

One thing comes to mind is that a pilot should keep the ability to turn off a transponder. If the transponder is sending faulty information, the pilot might want to turn it off. But it would be nice if the system sent a signal that indicated that the transponder was being switched off (as opposed to burning up in flames). Protocol would require a pilot to call in and indicate what the problem was.

Then you could distinguish between the scenario where the cockpit blew up, where the pilot turned it off for a legitimate reason, and where the transponder was turned off by someone invading the cockpit (or a pilot/copilot that went off the deep end).

Quote: beachbumbabs

I've skipped a lot, trying to pick out what's pertinent to this mystery, but this is how what everyone's saying over there can be correct at the same time, even though it seems contradictory. The tag could have continued on the projected track, without a real target after transponder signal loss, which would not be unusual at the range from the shore, towards Vietnam for an hour, easily. The transponders could have been turned off deliberately, making it difficult to track, and then an untracked turn could be made if the aircraft went deliberately silent.

AF447 wasn't missing until people in Orly Airport near Paris were getting ready for its arrival in about an hour.... and the plane had gone down shortly after leaving South America. I wonder how far its "tag box" coasted?

The only thing I would wonder about is that certain countries who are terrorist concerned or smuggling concerned seem to have very precise radar for ships and planes. If a yacht approaching to check in to customs has a local fishing boat go anywhere near it, the customs people often come out and follow it in under close escort thinking there may have been a drug transfer. The coverage is extensive and precise. This seems to include airspace though not civil aircraft routes. Malaysia is fairly rich, though corrupt, and smugglers are watched if they don't make proper payoffs. Also terrorist activity is feared though mainly in remote areas of Islamic fundamentalist domination. Australia requires 96 hours of prior notification of port of arrival for a pleasure yacht and complete listing of all persons aboard. Aruba is less strict but you can cook hamburgers in their radar coverage zones.

One possibilty of suddenly going to zero altitude is cycling the switch through Mode C-off while turning it to totally off. I wonder how long the altitude data coasts if the tag is coasting?

I'm not if China wants to reveal the quality of its satellite images, but China could easily give coordinates rather than images.

Quote: beachbumbabs

the whole thing feels like the EgyptAir the copilot took down. Between the 2 false passport men who both booked 1 way tickets and the absence of crew communications, for a relatively short hop there would be only 2 people in the cockpit, so if one was a screwball, he could easily have done something about the other, as simple as locking him out of the cockpit on a bathroom break. And if they thought there was a need, the 2 guys in the back could take over the cabin long enough to kill the airplane.

They have named the co-pilot, who I am guessing when all is said and done will be shown to have crashed the plane into the ocean, hoping to be an Islamic martyr, possibly with assistance from our two stolen passport friends.

If there is an electrical fire the pilots may be a bit busy dealing with thick black smoke, hot melting rubber and what that does to their nylon/dacron uniforms. Grabbing the radio mike in the midst of all that is perhaps a task that is lower on the list of priorities than you might think. Setting a transponder to 7700 for an emergency or 7500 for Pilot is no longer in command of the aircraft is a nice thing to do but it can be difficult to achieve under certain circumstances. Tire explosions are rare but catastrophic at altitude. If half the panel is not working and the other half of the panel is suddenly working but not reliable, it can take time to figure out what to isolate electronically and what to keep.

Quote: SOOPOO

They have named the co-pilot, who I am guessing when all is said and done will be shown to have crashed the plane into the ocean, hoping to be an Islamic martyr, possibly with assistance from our two stolen passport friends.

Someone on TV said that it is very unlikely that the pilot would leave to go to the head just as they were entering Vietnam airspace. Although their is very little precedent, the copilot who wants to take over the plane does not try and overpower the pilot, but waits until he is alone and the pilot is in the head. For this reason he was discounting the suicidal co-pilot hypothesis.

Of course, with no data to look at it, there is no end to scenario building.